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Proposed LDAS validation experiments with Oklahoma Mesonet and ARM/CART observations


Comparison between LDAS forcing and the locally observed forcing shows a general agreement between these two datasets, as a result of forcing validation. The discrepancy between the model generated hydrological variables,especially soil moisture and the observations still exists. Now we are trying to run the models with the locally observed forcing and the local land surface characteristics to separate the uncertainties associated with the forcing and the models.

Experiment Setup

The following four runs will be carried out by all modeling group.

  • EXP000 -------original LDAS run
    • The forcing files ARE THE ORIGINAL FULL-DOMAIN NASA FORCING. The land mask is here . This is a binary file (464*224 pixles) with 1 indicating land and 0 indicating water. This mask consists 72 oklahoma mesonet stations, 24 ARM/CART station, 19 Illinois stations and 14 HPRCC stations in Nebrask. You can use the following GrADS control file to display the mask.

  • EXP111 -------all available local forcing are used
    • The forcing files are available here , or
      ftp as anonymous user
      cd /pub/luo/EXP111
      mget *.tar

      This set of forcing includes all the possible locally observed variables. It is in exactly the same format as original LDAS forcing, but the following variables are substituted by local forcing.

      TMP  ...............................USE LOCAL TEMPERATURE
      SPFH ...............................USE LOCAL SPECIFIC HUMIDITY
      PRES ...............................USE LOCAL PRESSURE
      UGRD ...............................USE LOCAL UGRD
      VGRD ...............................USE LOCAL VGRD
      ETA APCP
      DSWRF...............................USE LOCAL SHORTWAVE
      APCP ...............................USE LOCAL PRECIP instead of APCP
      You basically do not have to change anything when using this forcing. If the local PRECIP or SHORTWAVE is not available, you should use ETA PRECIP and ETA shortwave, which is the standard way in original LDAS rerun.

      This different land mask is used in this run.

      This is a binary file (464*224 pixles) with 1 indicating land and 0 indicating water. This mask consists 72 oklahoma mesonet stations, 13 ARM/CART station. Because We only have local forcings over these stations. You can use the following GrADS control file to display the mask.

  • EXP111-2 -------EXP111 forcing with local soil texture map and Cosby/Rawl parameter table
    • Using the EXP111 forcing and one of the two soil map: multilayer or 1 layer . This soil map is derived from the local observations at those stations. It is probably not the most predominant soil type in the grid, but the soil type at the point where soil moisture are observed.

      The file gives the OK Mesonet station id or ARM/CART station id, lat and lon, x and y in the standard LDAS grid, soil type in 4 layers or intergrated to 1 layer using the program Matthew Rodell provided. (Thanks!). VIC and NOAH model can only use the intergrad 1 layer soil texture, while MOSAIC can use the multilayer one. Because we don't have all the information, we can only provide soil information for 73 stations out of 85. Other station you should use the the original soil texture you have for rerun. If it is a big problem for you, let me know. Using the following FORTRAN code to read the file:

            character(len=4) :: siteid
            real :: lat, lon
            integer, dimension(4) :: tex
            integer :: x, y
            read(*,300)siteid,lat, lon, x, y, (tex(j),j=1,4)
      300 format(a4,3x,f9.4,3x,f9.4,3x,i4,3x,i4,3x,i2,3x,i2,3x,i2,3x,i2)
      	Here is the soil type code:
       TEX = 1	!CLAY
       TEX = 2	!SILTY CLAY
       TEX = 3	!SANDY CLAY
       TEX = 4	!CLAY LOAM
       TEX = 7	!LOAM
       TEX = 8	!SILTY LOAM (and SILT)
       TEX = 9	!SANDY LOAM
       TEX = 10	!LOAMY SAND
       TEX = 11	!SAND
      Here is the message from Ken Mitchell regarding the experiment:
      Brian, Justin, Eric, Dag, Qingyun, Lifeng, Alan,                                   
      Recall from our last N-LDAS phone conferences of 11 and 18 April, we               
      agreed to make another reduced-grid retro N-LDAS run, designated as Case           
      "111-2" (using OU Mesonet observed local forcing from Lifeng Luo on the            
      "OU" 84-pixel reduced grid), in which the "-2" of "111-2" designates our           
      use of:                                                                            
      A) common "locally observed" soil texture class index at each of the 84            
      pixels (the index range being 1-12 corresponding to the 12 soil class              
      indices of Cosby et al.)                                                           
      We are to use Lifeng Luo's "map" of the soil texture class index at the            
      84-pixels (this map is based on the OU Mesonet-folk determined locally             
      sampled soil texture).                                                             
      B) common 12-class table of FOUR soil physical parameters                          
           1 - porosity                                                                  
           2 - B-parameter                                                               
           3 - saturated soil matric potential                                           
           4 - saturated soil hydraulic conductivity                                     
      In response to Brian's email below, clarifying what he used in MOSAIC, I           
      direct that in this Experiment 111-2 that all four models (MOSAIC, NOAH,           
      VIC, SAC) use the "Cosby/Rawls" soil parameter table from Qingyun Duan,            
      given below by Brian, namely the " Cosby parameters for everything                 
      except for Ksat from Rawls" (WITHOUT substituting  Rawls values for the            
      sand class, except for Ksat of course).                                            
      LISTED ABOVE  UNDER "B". Otherwise continue to use what your model has             
      been using, except of course for those parameters that your model                  
      calculates from the above four.                                                    
      CAUTION:  double check that you adhere to your model's units convention            
      and sign convention for these four soil parameters (e.g. in some models            
      the saturated soil matric potential should be given as a negative value            
      if I recall).                                                                      
      ALSO:  In a closely related follow-on experiment, I propose we also                
      execute an Experiment "111-3", in which in addition to the above common            
      four soil parameters and common soil type map, we also commonly adopt              
      the following:                                                                     
      1 - saturated soil thermal conductivity from the table below                       
      2 - field capacity from the table below                                            
      3 - wilting point from the table below                                             
      4 - common universal vegetation class of "grass cover" at each of the 84           
      5 - common vegetation parameters for "grass cover" to the extent that we           
      can (e.g. minimal stomatal resistance, seasonal cycle of fractional area           
      of green vegetation cover, etc -- the source and value of these will               
      have to be discussed at our next N-LDAS phone conference of April 26, 10           
      Ken Mitchell                                                                       
       0.339  0.0854  0.0218  0.0692  3.7472E-05   2.79    0.92				 
       0.421  0.1467  0.0599  0.0363  1.8056E-05   4.26    0.82				 
       0.434  0.2242  0.1002  0.1413  6.3611E-06   4.74    0.60				 
       0.476  0.3626  0.1772  0.7586  2.1389E-06   5.33    0.25				 
       0.476  0.3626  0.1772  0.7586  2.1389E-06   5.33    0.10				 
       0.439  0.2881  0.1393  0.3548  1.4444E-06   5.25    0.40				 
       0.404  0.2527  0.1438  0.1349  9.7222E-07   6.77    0.60				 
       0.464  0.3837  0.2477  0.6166  1.1944E-06   8.72    0.10				 
       0.465  0.3420  0.2144  0.2630  3.3333E-07   8.17    0.35				 
       0.406  0.2930  0.2053  0.0977  2.7778E-07  10.73    0.52				 
       0.468  0.3750  0.2597  0.3236  4.4444E-07  10.39    0.10				 
       0.457  0.3117  0.2240  0.4677  5.2778E-07  11.55    0.25				 
       The soil classes (rows):									 
          1   S	  Sand										 
          2   LS    Loamy sand									 
          3   SL    Sandy loam									 
          4   SIL   Silt loam 									 
          5   SI    Silt										 
          6   L	  Loam										 
          7   SCL   Sandy clay loam 								 
          8   SICL  Silty clay loam 								 
          9   CL    Clay loam 									 
         10   SC    Sandy clay									 
         11   SIC   Silty clay									 
         12   C	  Clay										 
      soil property definition (Col.):                                               
        1:      Porosity                                                              
        2:      Field capacity                                                        
        3:      Wilting point                                                         
        4:      Saturated soil matric potential (in m of h2o)                         
        5:      Saturated soil hydraulic conductivity (in m/s)                        
        6:      B parameter                                                           
        7:     Quatz content                                                          

Inital condition

    Use the following initial conditions

    Use the rerun initial condition from Dag Lohmann to start EXP000 from the very beginning, running through the rerun period( 3 year). Use the models states at 00z01JAN98 as initial conditions for other runs.

Modeling Period

    00Z01JAN98---23Z30SEP99 for EXP111
    00Z30SEP96---23Z30SEP99 for EXP000

Submitting Results

    Please finish these runs AS SOON AS POSSIBLE. VIC output can be stored somewhere on since I have access to this machines. MOSAIC output can be stored on NOAH model output can be ftped to Rutgers machine through existing account. Just submit the output in grib format, no script is needed to extract the data. We will take care of it.
Maintained by Kenneth Mitchell and Youlong Xia
Last updated: Tue Jul 8 13:56:50 2008 UTC
Constructed and Developed by Lifeng Luo